Fluid powered oscillatory drive

ABSTRACT

A high speed reciprocatory tool such as a drill has a reciprocating system including a pair of diaphragms mounted for deflection within a chamber; the diaphragms are coupled to deflect coaxially and simultaneously, there being inertial mass that moves with the diaphragms; and valve means controls transmission of motive fluid pressure from a chamber inlet to impinge against the diaphragms in alternating sequence to effect system reciprocation.

United States Patent Dexter Apr. 4, 1972 [54] FLUID POWERED ()SCILLATORY 2,702,006 2/1955 Bachert ..9l/329 DRIVE 2,798,440 7/1957 Holl ....9l/329 3,236,441 2/ 1966 Russell ..92/329 [72] Inventor: Wilbur H. Dexter, Inglewood, Calif. v

Prima Examiner-Paul E. Maslousk [73] Assignee: John H. Ransom Lahoratorles, Inc., Los g, &Ha'efliger y Angeles, Calif. a part interest [22] Filed: Dec. 12, 1969 ABSTRACT [21] Appl No: 384,407 A high speed reciprocatory tool such as a drill has a reciprocating system including a pair of diaphragms mounted for deflection within a chamber; the diaphragms are coupled [52] U.S.Cl ..91/52,9l/329,9l/335 to deflect coaxially and simultaneously, there being inertial [51] lnt.Cl i ..F15b 13/02, F01] l5/l4 mass that moves with the diaphragms; and valve means con- [58] Field of Search ..'.;.5l/59 SS; 77/32.3;9l/329, trols transmission of motive fluid pressure from a chamber 91/335, 52; 82/36 inlet to impinge against the diaphragms in alternating sequence to effect system reciprocation. [56] References Cited 4 C] i 3 Drawing Figures UNITED STATES PATENTS 944,255 12/1909 Bong 91/52 42 79 60- a6 4/ 37 22 r-[i] 3a 3 55 74 75 i 5 -22! {Z -g9. I!

29/ l9 3/ 72 56 a4 5 74/ v 27 53 5 f i i 73 FLUID POWERED OSCILLATORY DRIVE BACKGROUND OF THE INVENTION This invention relates generally to high speed reciprocatory apparatus as used for work processing, and more particularly concerns a fluid apparatus capable of reciprocation at rates upwards of 1,000 cycles per second, for use in drilling.

High speed drilling apparatus in the past has taken the form of ultrasonic or magnetostrictive devices which are electrically powered. Such devices are expensive and require power sources of undesirably high capacity. Accordingly, there is a need for simple, relatively inexpensive apparatus characterized by relatively low power consumption or requirements, and capable of rapidly drilling holes in brittle or fracturable material, as for example glass.

SUMMARY OF THE INVENTION It is a major object of the invention to provide a solution of the above problem, in a fluid apparatus fulfilling the need as outlined above. Basically, the device of the invention comprises a chamber having inlet and outlet ports; a reciprocatory system extending within the chamber and including a pair of diaphragms mounted for deflection relative to the chamber; means coupling the diaphragms to deflect generally coaxially and simultaneously, there being inertial mass associated with the coupling means to reciprocate as the diaphragms deflect in opposite directions to provide system inertia; and valve means to control transmission of motive fluid pressure from the inlet to impinge against the diaphragms in alternating sequence, thereby to effect system reciprocation at very high speed. As will be seen, the valve means is typically located to direct and control gas transmission to one and then to the other of the diaphragms in response to system reciprocation, the construction being simple and highly effective.

Additional objects and advantages include the provision of valve means including a pair of stoppers carried by the system to reciprocate and alternately engage valve seats surrounding gas ports in the chamber; the provision of annular inserts defining the gas ports within the chamber so that the coupling means for the diaphragms extends through such ports; the provision of a mass in the form of a flange located between the stoppers and on a stern coupling the diaphragms; the provision of adjustable orifice means communicating with the outlet ports to variably restrict the flow of gas from the chamber, thereby to control the rate of system reciprocation; and the inclusion of a tool such as a drill connected with the reciprocating system.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is an elevation showing one form of tool incorporating the invention; 1

FIG. 2 is an enlarged section taken on line 2-2 of FIG. 1;

and

FIG. 3 is an elevation illustrating a drilling operation using the tool of FIGS. 1 and 2. 1

DESCRIPTION OF PREFERRED EMBODIMENT in the drawings, the tool includes a chamber 11 having a cylindrical body 12 and end caps 13 and 14 with thread connection to the body at 15 and 16.

A reciprocating system extends within the body, and includes a pair of metallic diaphragms l7 and 18 mounted for deflection relative to the chamber and in the direction of axis 19. The system includes means coupling the diaphragms to yieldably deflect generally coaxially and simultaneously, there being a mass associated with the coupling means to reciprocate as the diaphragms deflect in opposite directions to provide system inertia. A significant part of such mass is that formed by flange 20 retained on the coupling stem or rod 21 between like spacers 22 and 23. The latter are in turn retained on the rod by the nuts 24 and 25 and elements 26, 27 and 28 as illustrated.

The chamber 1 1 has a fluid inlet port 29, and outlet ports 30 and 31; and valve means is provided within the chamber to control transmission of motive fluid (as for example gas or other fluid) pressure from the inlet to impinge against the diaphragms in alternating sequence, thereby to effect system reciprocation. In this regard, the valve means is located to direct gas pressure transmission repeatedly to one and then to the other diaphragm in response to system reciprocation. For this purpose, the valve means may include a pair of valves or stoppers, as for example annular bosses 33 and 34 on the spacers 22, carried by the system to reciprocate therewith and alternately engage or nearly engage valve seats surrounding gas ports in the chamber. Such seats may be annular and located at 35 and 36 about the gas ports 37 and 38 formed by the inserts 39 and 40 received in chamber 11. The ports also receive the rod and the spacers 22 and 23, with sufficient clearance to pass gas pressure to the diaphragms. In so passing, the pressurized gas flows through ports formed at 41 and 42 between element 26 and insert 39, and through ports formed at 43 and 44 between element 27 and insert 40. The peripheries of the diaphragms may be retained, as shown, between inserts 39 and 40 and the end caps 13 and 14, respectively.

In operation, gas pressure from a source 46 is supplied to the central zone 47 within the body 12 as via line 48 and entrance port 29. Assuming that the reciprocatory system is in down position (although it need not be for commencement of operation) with stopper 34 seated at 36 and closing off lower ports or passages 38, 43 and 44, the gas pressure passes through open upper ports 37, 41 and 42 to impinge upon the upper diaphragm exposed to space 50. The upper diaphragm deflects upwardly and carries the system with it, to carry upper stopper 33 towards seat 35, and to retract lower stopper 34 from seat 36. The displacement is sufficient, considering the effect of system inertia, to reverse the operation of the diaphragms, in that the lower diaphragm 18 is then exposed to impingement of gas pressure passing through open ports or passages 38, 43 and 44 to lower space 51. In practical effect, the proportioning of the components is such as to cause a rapid oscillation of the system, say'within the range 3,000 to 12,000 cycles per second, with supply pressures within the range 20 psi. to 60 psi. inlet pressure, although other speeds and pressures may be used and attained. Typical reciprocatory travel of a tool 55 carried by the system (as via a collet 56) is within the range 0.0003 to 0.002 inches, although other strokes may be achieved.

Gas supplied to the spaces 50 and 51 may escape via ports 58 and 59 in the inserts 39 and 40 and the outlet ports 30 and 31 in the body 11, and little if any restriction to such escape is needed inasmuch as it is the sudden and rapid impinging of the gas pressure on the diaphragms and elements 26 and 27 which produces the desired rapid reciprocation. Note the provision of annular seals at 60 and 61 to block gas pressure escape between the inserts 39 and 40 and the body 12.

On the other hand, means may be provided to communicate with either or both of the outlet ports 30 and 31 to variably restrict the escape of gas from the chamber, thereby to control the rate of system reciprocation. Identical examples of such control means are indicated at and 71, and each includes a hollow fitting 72 threaded at 73 into the body 11 to pass escaping gas via ports 74 and 75 to the exterior. In so passing, the gas flows over a seat 76 toward port 75, the exposure of the latter port being controlled by a diaphragm 77. Such control is varied by a set screw 79, as shown. In use, the frequency of reciprocation of the tool 55 may be controlled by advancing or retracting either or both of the set screws 79 associated with the control means 70 and 71.

FIG. 3 shows the flanged and tapered drill tip 80 drilling into the work 81 as the tip reciprocates endwise at high speed.

An aqueous or other slurry of abrasive granules (as for example Carborundum, emery, bort, etc.) may be fed at 82 to the drill hole 83 to aid in such drilling. The work may for example consist of otherwise fracturable or brittle material such as glass, in which a hole may be rapidly drilled with high accuracy and without risk of breakage. For example, a inch hole may be drilled in glass using a V4 horsepower motor to compress air as needed to drive the drill during drilling. This represents a great advantage over the power requirements (on the order of 10,000 watts) needed to drive ultrasonic or magnetostrictive apparatus now used for drilling such holes.

I claim:

1. In a high speed reciprocating apparatus for-driving a glass drill, the combination comprising a. a chamber having pressure fluid inlet and outlet ports,

b. a reciprocating system extending within the chamber and including a pair of metallic diaphragms mounted for deflection relative to the chamber, and means including a central stem coupling the diaphragms to deflect generally coaxially and simultaneously, said system projecting axially endwise to the exterior of the chamber for driving the drill, there being a mass in the form of a flange mounted on the stem to reciprocate rapidly therewith as the diaphragms deflect in opposite directions to provide system inertia, and

c. valve means to control transmission of motive fluid pressure from said inlet to impinge against the diaphragms in alternating sequence thereby to effect system reciprocation, said valve means including a pair of annular stoppers extending about the stem to reciprocate therewith and alternately approach valve seats surrounding fluid ports in the chamber, the means coupling the diaphragms extending through said fluid ports, and said mass located between said annular stoppers, and

d. adjustable orifice means communicating with at least one outlet port to controllably restrict escape of fluid from the chamber after fluid passes through at least one of said fluid ports.

2. The combination of claim 1 wherein the chamber includes annular inserts defining said fluid ports.

3. The combination of claim 1 wherein said outlet ports are exposed to the outer portions of the diaphragms.

4: The combination of claim 1 including a source of gas connected with the inlet port and under pressure between 20 and 60 p.s.i. 

1. In a high speed reciprocating apparatus for driving a glass drill, the combination comprising a. a chamber having pressure fluid inlet and outlet ports, b. a reciprocating system extending within the chamber and including a pair of metallic diaphragms mounted for deflection relative to the chamber, and means including a central stem coupling the diaphragms to deflect generally coaxially and simultaneously, said system projecting axially endwise to the exterior of the chamber for driving the drill, there being a mass in the form of a flange mounted on the stem to reciprocate rapidly therewith as the diaphragms deflect in opposite directions to provide system inertia, and c. valve means to control transmission of motive fluid pressure from said inlet to impinge against the diaphragms in alternating sequence thereby to effect system reciprocation, said valve means including a pair of annular stoppers extending about the stem to reciprocate therewith and alternately approach valve seats surrounding fluid ports in the chamber, the means coupling the diaphragms extending through said fluid ports, and said mass located between said annular stoppers, and d. adjustable orifice means communicating with at least one outlet port to controllably restrict escape of fluid from the chamber after fluid passes through at least one of said fluid ports.
 2. The combination of claim 1 wherein the chamber includes annular inserts defining said fluid ports.
 3. The combination of claim 1 wherein said outlet ports are exposed to the outer portions of the diaphragms.
 4. The combination of claim 1 including a source of gas connected with the inlet port and under pressure between 20 and 60 p.s.i. 